Exploring Earth's History and Life

Front

What does the fossil record show about life on Earth?

Back

Life forms have changed, diversified, and some have gone extinct over time.

Front

What can scientists infer when they find similar bone structures in the limbs of whales, bats, and humans?

Back

They share a common ancestor.

Front

What does the geologic time scale help scientists understand?

Back

The order and relative timing of events in Earth’s 4.6-billion-year history.

Front

Which process is responsible for the formation of mountains over millions of years?

Back

Plate tectonics

Front

The matching shapes of the coastlines of South America and Africa provide evidence for which scientific theory?

Back

Continents move due to plate tectonics.

Front

Which pattern in the fossil record would best support the idea of mass extinction?

Back

Sudden disappearance of many species in a short time.

Front

Which anatomical feature is most useful for determining evolutionary relationships among species?

Back

Similarities in bone structure

Front

What is the main purpose of dividing Earth’s history into eras and periods on the geologic time scale?

Back

To show major changes in life and geology over time

Front

Example of a geoscience process that changes Earth’s surface quickly:

• Mountain formation
• River erosion
• Volcanic eruption
• Plate movement

Back

Volcanic eruption

Front

What evidence supports the idea that continents were once joined together?

Back

Similar fossils found on different continents